Exercise 6 | Chemical Kinetics: Mechanisms

The activation energy for the decomposition of butene C4H8 in ethene C2H4 is 262 kJ.mol-1.

At 300K the rate constant is 7.23 x 10-10 s-1.

What is the rate constant at 65.0°C?

Arrhenius equation:

k = Ae-Ea/RT

 

k2 / k1 = Ae-Ea/RT2 / Ae-Ea/RT1

⇒ k2 / k1 = e-Ea/RT2 + Ea/RT1

⇒ k2 = k1 x e-Ea/RT2 + Ea/RT1

with T1 = 300 K and T2 = 65.0°C = 338 K

 

k2 = 9.73 x 10-5 s-1